2011 Particle Accelerator Conference - List of Authors (Pai, C.)

Paper	Title	Page
MOP191	RHIC Spin Flipper Status and Simulation Studies	447
	M. Bai, W.C. Dawson, Y. Makdisi, F. Méot, P. Oddo, C. Pai, P.H. Pile, T. Roser BNL, Upton, Long Island, New York, USA
	Funding: This work was supported by Department of Energy of U.S.A and RIKEN, Japan The commissioning of the RHIC spin flipper in the RHIC Blue ring during the RHIC polarized proton run in 2009 showed the detrimental effects of global vertical coherent betatron oscillation induced by the 2-AC dipole plus 4-DC dipole configuration . Additional three AC dipoles were added to the RHIC spin flipper in the RHIC Blue ring during the summer of 2010 to eliminate the vertical coherent betatron oscillations outside the spin flipper [2]. This new design is scheduled to be commissioned during the RHIC polarized proton run in 2011. This paper presents the status of the system as well as latest simulation results. M. Bai , T. Roser, C. Dawson, Y. Makdisi, W. Meng, F. Meot, P. Oddo, C. Pai, P. Pile, RHIC Spin Flipper New Design and Commissioning Plan, IPAC10 proceedings, IPAC 2010, Kyoto, Japan, 2010

TUP054	Mechanical Design of 56 MHz Superconducting RF Cavity for RHIC Collider	907
	C. Pai, I. Ben-Zvi, A. Burrill, X. Chang, G.T. McIntyre, R. Than, J.E. Tuozzolo, Q. Wu BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A 56 MHz Superconducting RF Cavity operating at 4.4K is being constructed for the RHIC collider. This cavity is a quarter wave resonator with beam transmission along the centreline. This cavity will increase collision luminosity by providing a large longitudinal bucket for stored bunches of RHIC ion beam. The major components of this assembly are the niobium cavity with the mechanical tuner, its titanium helium vessel and vacuum cryostat, the support system, and the ports for HOM and fundamental dampers. The cavity and its helium vessel must meet the ASME pressure vessel code and it must not be sensitive to frequency shift due to pressure fluctuations from the helium supply system. Frequency tuning achieved by a two stage mechanical tuner is required to meet performance parameters. This tuner mechanism pushes and pulls the tuning plate in the gap of niobium cavity. The tuner mechanism has two separate drive systems to provide both coarse and fine tuning capabilities. This paper discusses the design detail and how the design requirements are met.

TUP057	The Fundamental Power Coupler and Pick-up of the 56 MHz Cavity for RHIC	916
	Q. Wu, S. Bellavia, I. Ben-Zvi, C. Pai BNL, Upton, Long Island, New York, USA
	Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. A fundamental power coupler (FPC) is designed to obtain the ability of fast tuning the 56MHz SRF cavity in RHIC. The FPC will be inserted from one of the chemical cleaning ports at the rear end of the cavity with magnetic coupling to the RF field. The size and the location of the FPC are decided based on the required operational external Q of the cavity. The FPC is designed with variable coupling that would cover a range of power levels, and it is thermally isolated from the base temperature of the cavity, which is 4.2K. A 1kW power amplifier will also be used to close an amplitude control feedback loop. In this paper, we discuss the coupling factor of the FPC with the carefully chosen design, as well as the thermal issues.

TUP058	Fundamental Damper Power Calculation of the 56MHz SRF Cavity for RHIC	919
	Q. Wu, S. Bellavia, I. Ben-Zvi, M.C. Grau, G. Miglionico, C. Pai BNL, Upton, Long Island, New York, USA
	Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. At each injection and extraction period of RHIC operation, the beam frequency will be sweeping across a wide range, and some of the harmonics will cross the frequency of the 56MHz SRF cavity. To avoid cavity excitation during these periods, a fundamental damper was designed for the quarter-wave resonator to heavily detune the cavity. The power extracted by the fundamental damper should be compliant with the cooling ability of the system at all stages. In this paper, we discussed the power output from the fundamental damper when it is fully extracted, inserted, and during its movement.

TUP213	Research and Development toward the RHIC Injection Kicker Upgrade	1211
	W. Zhang, W. Fischer, H. Hahn, C. Pai, J. Sandberg, J.E. Tuozzolo BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A research and development work is on going toward the upgrade of the RHIC Injection Fast Kicker System. We report here the proposed nano-second pulse generator, the initial test result, the options of the deflector design, injection pattern, and the benefit to the future RHIC programs.

Paper

Title

Page

RHIC Spin Flipper Status and Simulation Studies

447

M. Bai, W.C. Dawson, Y. Makdisi, F. Méot, P. Oddo, C. Pai, P.H. Pile, T. Roser
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by Department of Energy of U.S.A and RIKEN, Japan
The commissioning of the RHIC spin flipper in the RHIC Blue ring during the RHIC polarized proton run in 2009 showed the detrimental effects of global vertical coherent betatron oscillation induced by the 2-AC dipole plus 4-DC dipole configuration *. Additional three AC dipoles were added to the RHIC spin flipper in the RHIC Blue ring during the summer of 2010 to eliminate the vertical coherent betatron oscillations outside the spin flipper [2]. This new design is scheduled to be commissioned during the RHIC polarized proton run in 2011. This paper presents the status of the system as well as latest simulation results.
* M. Bai , T. Roser, C. Dawson, Y. Makdisi, W. Meng, F. Meot, P. Oddo, C. Pai, P. Pile, RHIC Spin Flipper New Design and Commissioning Plan, IPAC10 proceedings, IPAC 2010, Kyoto, Japan, 2010

TUP054

Mechanical Design of 56 MHz Superconducting RF Cavity for RHIC Collider

907

C. Pai, I. Ben-Zvi, A. Burrill, X. Chang, G.T. McIntyre, R. Than, J.E. Tuozzolo, Q. Wu
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A 56 MHz Superconducting RF Cavity operating at 4.4K is being constructed for the RHIC collider. This cavity is a quarter wave resonator with beam transmission along the centreline. This cavity will increase collision luminosity by providing a large longitudinal bucket for stored bunches of RHIC ion beam. The major components of this assembly are the niobium cavity with the mechanical tuner, its titanium helium vessel and vacuum cryostat, the support system, and the ports for HOM and fundamental dampers. The cavity and its helium vessel must meet the ASME pressure vessel code and it must not be sensitive to frequency shift due to pressure fluctuations from the helium supply system. Frequency tuning achieved by a two stage mechanical tuner is required to meet performance parameters. This tuner mechanism pushes and pulls the tuning plate in the gap of niobium cavity. The tuner mechanism has two separate drive systems to provide both coarse and fine tuning capabilities. This paper discusses the design detail and how the design requirements are met.

TUP057

The Fundamental Power Coupler and Pick-up of the 56 MHz Cavity for RHIC

916

Q. Wu, S. Bellavia, I. Ben-Zvi, C. Pai
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
A fundamental power coupler (FPC) is designed to obtain the ability of fast tuning the 56MHz SRF cavity in RHIC. The FPC will be inserted from one of the chemical cleaning ports at the rear end of the cavity with magnetic coupling to the RF field. The size and the location of the FPC are decided based on the required operational external Q of the cavity. The FPC is designed with variable coupling that would cover a range of power levels, and it is thermally isolated from the base temperature of the cavity, which is 4.2K. A 1kW power amplifier will also be used to close an amplitude control feedback loop. In this paper, we discuss the coupling factor of the FPC with the carefully chosen design, as well as the thermal issues.

TUP058

Fundamental Damper Power Calculation of the 56MHz SRF Cavity for RHIC

919

Q. Wu, S. Bellavia, I. Ben-Zvi, M.C. Grau, G. Miglionico, C. Pai
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
At each injection and extraction period of RHIC operation, the beam frequency will be sweeping across a wide range, and some of the harmonics will cross the frequency of the 56MHz SRF cavity. To avoid cavity excitation during these periods, a fundamental damper was designed for the quarter-wave resonator to heavily detune the cavity. The power extracted by the fundamental damper should be compliant with the cooling ability of the system at all stages. In this paper, we discussed the power output from the fundamental damper when it is fully extracted, inserted, and during its movement.

TUP213

Research and Development toward the RHIC Injection Kicker Upgrade

1211

W. Zhang, W. Fischer, H. Hahn, C. Pai, J. Sandberg, J.E. Tuozzolo
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A research and development work is on going toward the upgrade of the RHIC Injection Fast Kicker System. We report here the proposed nano-second pulse generator, the initial test result, the options of the deflector design, injection pattern, and the benefit to the future RHIC programs.